Processing math: 100%
 Register Login 切换中文 中国高分子学术平台
Research Article | Updated:2023-05-22
    • Sensing Performance of POE-based Microcellular Composites with Higher Resilience

    • Xin-long Tian

      ,  

      Han-xiong Huang

      ,  
    • ACTA POLYMERICA SINICA   Vol. 54, Issue 2, Pages: 235-244(2023)
    • Affiliations:

      Laboratory for Micro/Nano Molding & Polymer Rheology, Guangdong Provincial Key Laboratory of Technique and Equipment for Macromolecular Advanced Manufacturing, South China University of Technology, Guangzhou 510640

    • Author bio:

      Han-xiong Huang, E-mail: mmhuang@scut.edu.cn

    • DOI:10.11777/j.issn1000-3304.2022.22224    

      CLC:
    • Published:20 February 2023

      Published Online:21 September 2022

      Received:05 June 2022

      Accepted:29 July 2022

    Scan for full text

  • Cite this article

    PDF

  • Tian Xin-long,Huang Han-xiong.Sensing Performance of POE-based Microcellular Composites with Higher Resilience[J].ACTA POLYMERICA SINICA,2023,54(02):235-244. DOI: 10.11777/j.issn1000-3304.2022.22224.

  •  
  •  
    Sections

    Abstract

    Poly(ethylene-co-octene)/multi-walled carbon nanotubes/carbon fibre (POE/MWCNTs/CF, 90:5:5, W/W/W) composites were prepared by melt-mixing, and the composites were then foamed in a batch process using supercritical carbon dioxide foaming method. The cell structure was analyzed for the microcellular samples prepared at foaming temperatures of 55, 60 and 65 ℃, and its effect was emphasized on the compression properties of the microcellular samples and the piezoresistive response (sensitivity and linear response range) of the assembled sensors. It was demonstrated that the microcellular sample foamed at 55 ℃ exhibited a relatively uniform cell structure, a narrower cell diameter distribution (mainly in the range of 10‒30 μm), and moderately thick and highly continuous cell walls, which endowed the microcellular sample with higher resilience, compression strength, compression modulus and electrical conductivity. The sensor assembled with this microcellular disk had a wider linear response range (0‒30% compression strain) and higher sensitivity (strain factor of 1.67), which were analyzed based on the cell structure. The sensor exhibited faster piezoresistive response and recovery performance and good repeatability, and showed higher stability and durability in the 1000 cycles of cyclic compression/release test with 30% strain. Moreover, the sensor could monitor typical human motions, such as finger pressing, elbow bending, squatting, and foot stepping, which corresponded to a wider compressive strain range . The results demonstrate that the microcellular conductive composites with more uniform cell structure and moderately thick and highly continuous cell walls foamed by supercritical fluid foaming method have good sensing performance.

    transl

    Graphic Abstract

    abstract

    通过釜压发泡法制备乙烯-辛烯共聚物(POE)基微孔复合材料圆片;由其封装成的传感器具有较宽的线性响应范围和较高的灵敏度,能检测典型的人体运动.

    transl

    Keywords

    Poly(ethylene-co-octene)/multi-walled carbon nanotubes/carbon fibre composite; Supercritical carbon dioxide foaming; Microcellular structure; Resilience; Sensing performance

    transl

    柔性压力传感器因具有质量轻、延展性、可调检测范围等优点,越来越多地应用在智能穿戴、人体运动和健康检测等领域[

    1,2]. 根据传感机理,可将柔性压力传感器分为压阻式、电容式、压电式和摩擦起电4种类型[3],其中压阻式压力传感器由于结构简单、制造成本较低等被广泛研究.
    transl

    柔性压阻式压力传感器的传感基片通常由聚合物基导电复合材料制备. 其中聚合物基体一般为具有较高柔软性和伸长率的弹性体材料,如聚二甲基硅氧烷(PDMS)[

    4,5]、热塑性聚氨酯(TPU)[6~8]、橡胶[9,10]等;常用的导电填料包括碳纳米管(CNT)[5~7,11,12]、炭黑(CB)[4,8,13]和混合填料[9,14~17]等. 目前,在导电复合材料内部形成多孔微结构或在其表面制备微结构是提高传感器性能的2种主要方法,其中多孔微结构可提高传感基片的柔软性和可压缩性,有利于提高传感器的灵敏度等传感性能. 超临界流体发泡[7,10,12~14,18~20]是一种环境友好的制备导电多孔材料的方法. Rizvi等[7]采用超临界二氧化碳(Sc-CO2)发泡方法,对挤出制备的TPU/多壁碳纳米管(MWCNTs)纳米复合材料进行发泡,发现微孔纳米复合材料的压阻行为取决于MWCNTs含量和泡孔结构,并分析了其压阻机理. Fei等[12]采用Sc-CO2发泡法,对溶液混炼制备的TPU/MWCNTs纳米复合材料进行发泡,所制备的含5 wt% MWCNTs的微孔复合材料具有较高的灵敏度和较宽的线性响应范围. 然而,关于多孔材料的泡孔结构和内部导电网络 对传感性能影响的研究还不够充分、深入.
    transl

    与TPU、PDMS和橡胶等弹性体相比,乙烯-辛烯共聚物(POE)具有抗冲性能优异、热稳定性好、易加工等优点,被用作增韧剂(如增韧聚丙烯)或改性剂,关于以POE为基体制备多孔材料用于传感方面的研究还少有报道. Xu等[

    20]采用Sc-CO2发泡法制备了具有隔离网络结构的POE/CNT微孔复合材料,其具有高的电导率和电磁屏蔽性能,但未研究泡孔结构对微孔材料回弹性和传感性能的影响. 本文通过熔体混炼制备POE/MWCNTs/碳纤(CF)复合材料,采用Sc-CO2作为物理发泡剂对其进行釜压发泡,分析不同发泡温度下制备的微孔样品的泡孔结构,着重研究其对微孔样品压缩性能和传感器压阻响应的影响,并将传感器应用于人体运动检测.
    transl

    1 实验部分

    1.1 原料和设备

    POE,牌号8150,辛烯含量为25 mol%,密度0.868 g/cm3,熔体指数0.5 g/10min (2.16 kg,190 ℃),美国陶氏化学有限公司;MWCNTs,牌号XFQ038,直径8~15 nm,南京先丰纳米材料科技公司;CF,直径7 μm,深圳碳稀技术有限公司;CO2,工业级,纯度99.5%,市售.

    transl

    转矩流变仪,型号RTOI-55/20,广州普同实验分析仪器公司;模压机,型号CH-0203,东莞创 宏仪器设备有限公司;高压釜发泡装置,主要由高压计量泵(型号500D,美国ISCO公司)和高压釜(型号DDC-1000N,盛世致远(北京)科技有限公司)构成.

    transl

    1.2 样品制备

    将POE、MWCNTs和CF真空干燥8 h后,按90:5:5的质量比进行预混,加入转矩流变仪中进行混炼,制备复合材料. 混炼温度、转子转速和混炼时间分别设置为150 ℃、60 r/min和15 min. 将制备的复合材料放入模具型腔,将模具置于模压机中,在170 ℃下加热15 min后,在12 MPa的压力下保持15 min,冷却、脱模制得尺寸为100 mm × 100 mm × 1 mm的片材. 从片材中裁出直径为15 mm的圆片.

    transl

    将上述圆片置于高压釜发泡装置中,采用Sc-CO2为物理发泡剂,通过快速泄压方式制备发泡样品,发泡过程详见文献[

    21]. 发泡采用的参数为:饱和时间和饱和(发泡)压力分别固定为2 h和9 MPa,饱和(发泡)温度为55、60和65 ℃. 泄压时,在0.5 s内使高压釜内的压力降至大气压. 为固定泡孔结构,卸压后,迅速取出发泡样品装入样品袋中,置于冰箱中冷冻12 h. 从发泡样品中裁出直径为15 mm的微孔圆片,用于测试与表征.
    transl

    1.3 测试与表征

    1.3.1 复合材料的微观结构和热性能

    将制备的POE基复合材料片材置于液氮中浸泡4 h后脆断,对脆断面进行真空喷金,采用扫描电子显微镜(SEM;型号Phenom Pure,荷兰Phenom)观察复合材料中MWCNTs和CF的分散和分布.

    transl

    从制备的复合材料片材中切出约5 mg的薄片,置于示差扫描量热仪(DSC 3;型号METTLER,瑞士)中,在氮气气氛下以10 ℃/min的升温速率从25 ℃升温至200 ℃,恒温5 min消除热历史后降至常温,再以10 ℃/min的升温速率升温至200 ℃,记录升温曲线.

    transl

    1.3.2 发泡样品的泡孔结构、压缩性能和电导率

    将发泡样品置于液氮中浸泡4 h后脆断并喷金,采用上述SEM观察脆断面的泡孔结构. 利用Image-Pro Plus软件对SEM照片进行分析,获得各泡孔的直径,计算其平均值作为泡孔平均直径,并由下式计算泡孔密度N (cells/cm3).

    transl

    N=(ncellA)3/2 (1)

    式中,ncell为所分析的SEM照片上泡孔的个数,A为泡孔统计区域的真实面积(单位为 cm2).

    transl

    采用电动拉压力试验机(ZQ-990B,东莞智取精密仪器有限公司),对微孔圆片进行多循环压缩/卸载测试,以残余应变(即每一次压缩/卸载后压缩应力回复为0时对应的应变[

    22])表征其回弹性. 测试时压缩/卸载速度为3 mm/min,应变为50%. 对微孔圆片进行3 mm/min加载速度的压缩测试,获得应力-应变曲线,取50%应变时对应的应力值作为微孔圆片的压缩强度,对曲线的线性应变区进行拟合,获得微孔圆片的压缩模量. 测试5个微孔圆片,结果取平均值.
    transl

    将复合材料微孔圆片夹在两片铜箔之间,采用静电计(MT6514S,美国 Keithley)测量其体积电阻(R). 采用下式计算微孔圆片的电导率(σ):

    transl

    σ=L/RS (2)

    式中,LS分别为微孔圆片的厚度和其与单片铜箔之间的接触面积. 测试5个微孔圆片,结果取平均值.

    transl

    1.3.3 传感器的传感性能

    将复合材料微孔圆片夹在两片铜箔之间,将其贴在聚酰亚胺(PI)基底膜上,并用聚乙烯(PE)薄膜作为保护膜,以封装成传感器(图1),由55、60和65 ℃发泡温度下制备的微孔圆片封装成的传感器分别记为Sensor-55、Sensor-60和Sensor-65. 使用电动拉压力试验机对传感器施加压力(传感器发生相应的应变),使用静电计测量传感器的电阻值,测试时采样率为10 S/s.

    transl

    fig

      

    Fig. 1  Schematics of assembled sensor in this work.

    icon Download:  Full-size image | High-res image | Low-res image

    2 结果与讨论

    2.1 复合材料的微观结构和热性能

    高分子复合材料中导电填料的分散和分布不仅影响其导电性能,还会影响其黏弹性,进而影响其发泡材料的泡孔结构等[

    21],因此需要研究所制备POE/MWCNTs/CF复合材料中MWCNTs和CF的分散和分布. 图2为复合材料脆断面的SEM照片. 可见,CF分布较稀疏,难以形成有效的导电网络;CF周围的MWCNTs分布较为均匀且密集(见图2中放大的SEM照片),不仅可较大概率地形成导电网络,还可与CF相互搭接形成导电通路,从而提高复合材料的导电性(电导率为9.98×10-6 S/cm).
    transl

    fig

      

    Fig. 2  SEM images of cryofractured surface of POE/MWCNTs/CF composite sample.

    icon Download:  Full-size image | High-res image | Low-res image

    图3为POE/MWCNTs/CF复合材料的DSC升温曲线,图中同时给出了POE的升温曲线(其测试薄片的制备过程与复合材料的相同),以做比较. 可见,POE的熔点为60.8 ℃;加入的MWCNTs和CF使POE熔点降低至55.2 ℃. 这可能是由于填料的加入破坏了POE分子中聚乙烯链段所形成的微晶区,减少物理交联点,使POE可在较低温度下熔融.

    transl

    fig

      

    Fig. 3  DSC melting curves of POE and POE/MWCNTs/CF composite samples.

    icon Download:  Full-size image | High-res image | Low-res image

    2.2 发泡样品的泡孔结构、压缩性能和电导率

    参考上述的DSC测试结果,设置3种饱和(发泡)温度(55、60和65 ℃),研究其对POE/MWCNTs/CF复合材料发泡样品泡孔结构的影响. 图4显示了这3种发泡温度下发泡样品的脆断面SEM照片及其泡孔直径分布(图中给出了泡孔的平均直径、密度和发泡样品的膨胀比). 可见,3种温度下发泡的样品均呈闭孔结构,泡孔直径分布符合高斯分布. 55 ℃发泡样品的泡孔结构较为均匀,泡孔直径分布较窄(主要在10~30 μm范围内),泡孔壁较厚(5~6 μm),见图4(a);60 ℃发泡样品的泡孔直径分布均匀性要差些,泡孔的平均直径较小(13.7 μm)、密度较高(1.48×108 cells/cm3),泡孔壁较薄(2~3 μm),见图4(b);65 ℃发泡样品的泡孔直径明显较大、泡孔密度较低,泡孔直径分布明显较宽,泡孔壁很薄(1~2 μm),见图4(c). 此外,发泡样品的膨胀比(测试方法见文献[

    21])随发泡温度的提高呈现较明显的增加.发泡样品的泡孔结构、泡孔尺寸和膨胀比的差异归因于饱和温度的改变导致复合材料不同的黏弹性以及Sc-CO2在材料中不同的溶解度和扩散速率.
    transl

    fig

      

    Fig. 4  SEM images of cryofractured surfaces and cell diameter distributions for foamed POE/MWCNTs/CF composite samples prepared at foaming temperatures of 55 ℃ (a), 60 ℃ (b), and 65 ℃ (c) (mean diameters and densities of cells and expansion ratios of foamed samples are given in right columns).

    icon Download:  Full-size image | High-res image | Low-res image

    对上述3种发泡温度下制备的复合材料微孔圆片进行50次、50%应变的循环压缩/卸载测试,其中第1、10、20、30、40和50次循环的压缩应力-应变曲线如图5(a)~5(c)所示.可见,3种微孔圆片的各次压缩曲线与卸载曲线均呈现不重叠现象,表明其存在能量耗散和不可逆的塑性形变.根据图5(a)~5(c)得到微孔圆片残余应变与循环次数的关系曲线,结果见图5(d).可见,55和60 ℃制备微孔圆片的残余应变随循环次数而增加的程度较小,尤其是55 ℃制备微孔圆片的残余应变最小,回弹性最高;65 ℃制备微孔圆片的残余应变随循环次数而明显增加,回弹性明显较差.原因简述如下.对55 ℃微孔圆片,泡孔壁的厚度适中、连续性高,且泡孔结构和直径分布较均匀(图4(a)),使其在循环压缩/卸载过程中表现出较高的回弹性;与55 ℃微孔圆片相比,60 ℃微孔圆片虽然呈现较薄的泡孔壁,但其泡孔密度较高(图4(b)),较致密的泡孔壁有利于卸载后微孔圆片的回弹;而65 ℃微孔圆片的泡孔壁过薄(个别泡孔壁已破裂),且泡孔直径较大使泡孔壁较长(图4(c)),从而在压缩过程中泡孔壁易发生永久形变,降低微孔圆片的回弹性.

    transl

    fig

      

    Fig. 5  (a)‒(c) Stress-strain curves of multiple cyclic compression/release tests, (d) residual strain versus cycle number curves, (e) compression stress-strain curves, and (f) compression strengths, compression moduli and conductivities for microcellular POE/MWCNTs/CF composite disks prepared at three foaming temperatures.

    icon Download:  Full-size image | High-res image | Low-res image

    对复合材料微孔圆片进行50%应变的压缩测试,所得应力-应变曲线如图5(e)所示. 根据曲线得到微孔圆片的压缩强度和压缩模量,见图5(f). 可见,55 ℃微孔圆片的压缩强度和压缩模量(约630 kPa和2.95 MPa)明显比60和65 ℃微孔圆片的高. 图5(f)还显示了3种发泡温度下制备的微孔圆片的电导率. 可见,55 ℃微孔圆片的电导率(6.05×10-8 S/cm)比60和65 ℃微孔圆片的电导率(2.79×10-9和2.39×10-9 S/cm)高一个多数量级. 55 ℃微孔圆片呈现较高的压缩性能和电导率归因于其较厚且连续性高的泡孔壁,以及在泡孔壁中形成的较连续的填料网络.

    transl

    2.3 传感器的灵敏度及机理分析

    由上述3种发泡温度下制备的微孔圆片封装成传感器(Sensor-55、Sensor-60和Sensor-65;图1). 采用应变因子(GF)表征传感器的灵敏度,其计算公式为:GF = (ΔR/R0)/ε,式中R0ε和ΔR分别表示传感器的初始电阻、压缩应变和受压后的电阻变化值. 图6显示了这3种传感器的相对电阻变化(ΔR/R0)随应变的变化曲线. 可见,Sensor-55在0~30%和30%~50%应变范围内的ΔR/R0均与应变呈良好的线性关系,分别具有较高和低的GF (1.67和0.25);Sensor-60和Sensor-65在0~40%应变范围内呈现2~3段GF值不同的线性区,GF总体上较低,且在40%~50%应变范围内均出现了正压阻现象(即电阻随应变而增加).

    transl

    fig

      

    Fig. 6  Relative resistance change (ΔR/R0) versus strain curves for three kinds of sensors.

    icon Download:  Full-size image | High-res image | Low-res image

    3种传感器所呈现的灵敏度差异与其对应的微孔圆片的泡孔结构和泡孔壁上导电填料的分布密切相关. 下面结合图7所示微孔圆片中泡孔壁的典型SEM照片和形变示意图对此进行分析.

    transl

    fig

      

    Fig. 7  Typical SEM images of cell walls and schematics of their deformation in microcellular POE/MWCNTs/CF composite disks for (a) Sensor-55, (b) Sensor-60 and (c) Sensor-65.

    icon Download:  Full-size image | High-res image | Low-res image

    Sensor-55对应微孔圆片的泡孔壁较厚且连续性高(图7(a)),分布在泡孔壁中的导电填料(主要是MWCNTs)连通性较好. 在较低的压缩应变范围内,随应变的增加泡孔壁被逐渐压缩,由于泡孔的结构较均匀、直径分布较窄(图4(a)),泡孔壁的形变率较为均匀,这促进了泡孔壁中导电填料的搭接或相互接近,使该传感器的电阻随应变而逐渐减小,在0~30%的应变范围内具有较高的灵敏度和线性度;随应变的进一步增加(30%~50%范围内),泡孔壁因较厚而较难以被继续压缩,其形变接近饱和,传感器的电阻变化较小,从而呈现较低的灵敏度.

    transl

    Sensor-60尤其是Sensor-65对应微孔圆片的泡孔壁明显较薄(图7(b)和7(c)),分布在泡孔壁中的导 电填料的连通性要比Sensor-55中的差些. 在较低的应变范围内,较薄的泡孔壁易被压缩,促进泡孔壁中导电填料的搭接或相互接近,但由于泡孔直径分布较宽(图4(b)和4(c)),压缩过程中不同尺寸泡孔的形变存在先后和程度的差异,因此传感器在0~40%的应变范围内呈现2~3段GF值不同的线性区;进一步增加应变时(40%~50%),泡孔壁发生较大形变,使沿泡孔壁分布的导电填料部分被隔断(图7(b)和7(c)示意图中的虚线圆圈),连通性降低,从而出现了正压阻现象.

    transl

    采用冷冻干燥法[

    6]和牺牲模板法[7]可分别制备具有取向和双峰泡孔结构的TPU基导电微孔纳米复合材料,由其封装的传感器呈现较宽的线性响应范围(分别约为77%和60%),但灵敏度不够高(GF为1.5和1.22),压缩强度低(13.2和8 kPa). 本文采用Sc-CO2发泡法制备的POE基微孔材料所封装的传感器(Sensor-55),线性响应范围虽然窄些(30%),但灵敏度要高些(GF为1.67),尤其是其对应的微孔圆片具有明显较高的压缩强度(约630 kPa)和回弹性.
    transl

    2.4 传感器的力电行为和应用

    由上述结果可知,55 ℃发泡温度下制备的微孔圆片在压缩过程中呈现较高的回弹性,由其封装的传感器(Sensor-55)具有良好的线性响应范围和灵敏度. 对该传感器在不同的压缩速度和压缩应变下的电阻响应进行测试,所得R/R0随时间的变化曲线见图8(a)~8(c). 在3、6、12和18 mm/min这4种压缩速度(应变固定为25%)下,对Sensor-55依次进行10次循环加载/卸载测试,结果表明该传感器在4种压缩速度下均呈现较为快速的响应和恢复性能(图8(a)). 在5%、10%、15%、20%和25%这5种压缩应变(压缩速度固定为3 mm/min)下,分别对Sensor-55进行单循环和依次进行10次循环加载/卸载测试,重复5个周期,结果表明该传感器的电阻随应变增加而逐渐减小,5个周期内的重复性良好(图8(b)和8(c)). 进一步地,在3 mm/min压缩速度、30%应变下,对Sensor-55进行1000次(约8350 s)的循环压缩/释放测试,结果如图8(d)所示. 可见,在1000次的循环测试中,Sensor-55的R/R0基本保持稳定,表现出较高的循环响应稳定性和重复性,表明该传感器具有较好的耐用性.

    transl

    fig

      

    Fig. 8  Electromechanical behaviors of Sensor-55. Resistance change (R/R0) under (a) four different compression speeds (25% strain), (b) step cyclic strain in five cycles and (c) five different compression strains in ten compression/release cycles (3 mm/min compression speed); (d) durability test for 1000 compression/release cycles (3 mm/min compression speed and 30% strain).

    icon Download:  Full-size image | High-res image | Low-res image

    为发挥Sensor-55具有较宽线性响应范围、较高回弹性等优势,将其用于手指按压、肘部弯曲、深蹲和脚踩等典型人体运动的检测. 测试时,采用导线将Sensor-55接入静电计,记录其电阻随时间的变化,获得电阻变化(R/R0)随时间的变化曲线. 通过手指在Sensor-55上作用小压力(对应小压缩应变)并保持一段时间,其电阻快速减小并保持一较稳定的值,移开手指后,电阻快速回复至其初始值(见图9(a));将Sensor-55贴附在测试者肘关节的内侧,当测试者弯曲手臂对传感器施加一定的压力时,其电阻值快速减小,伸直手臂后电阻快速回复至其初始值(图9(b));将Sensor-55贴附在测试者的腘窝处或鞋底,测试者连续进行十余次的深蹲和站立或脚踩和脚跟抬起,深蹲或脚踩对传感器施加较大压力(对应较大压缩应变)时其电阻值较明显地减小,站立或脚跟抬起时电阻快速回复至其初始值(图9(c)和9(d)). 这些结果表明,Sensor-55能检测不同人体运动(对应较宽的压缩应变)所产生的压阻响应,具有较高的可靠性,因此该传感器在人体运动检测方面有着良好的应用前景.

    transl

    fig

      

    Fig. 9  Monitoring of typical human motions by using Sensor-55. Resistance change (R/R0) versus time curves during (a) finger pressing, (b) elbow bending, (c) squatting and (d) foot stepping.

    icon Download:  Full-size image | High-res image | Low-res image

    3 结论

    通过熔体混炼制备POE/MWCNTs/CF复合材料,采用Sc-CO2作为物理发泡剂在55、60和65 ℃ 3种发泡温度下对其进行釜压发泡. 55 ℃发泡样品的泡孔结构较为均匀,泡孔直径分布较窄(主要在10~30 μm内),泡孔壁较厚且连续性高,从而具有较高的回弹性、压缩强度(约630 kPa)、压缩模量(2.95 MPa)和电导率;60 ℃发泡样品泡孔的直径较小、密度较高,泡孔壁较薄;65 ℃发泡样品泡孔的直径明显较大、密度较低、直径分布明显较宽,泡孔壁很薄. 采用60和65 ℃下制备的微孔圆片封装的传感器在0~40%压缩应变范围内呈现2~3段GF值不同的线性区,GF总体上较低. 采用55 ℃下制备的微孔圆片封装的传感器在较宽的线性响应范围(0~30%应变)内具有较高的灵敏度(GF为1.67),在不同的压缩速度和压缩应变下均能呈现较快速的响应和恢复性能以及良好的重复性,在1000次(约8350 s)循环压缩/释放测试中呈现较稳定的压阻响应和良好的耐久性,且对不同的人体运动所产生的范围较宽的压力(对应较宽的压缩应变)具有较好的检测能力. 本文工作对采用超临界流体发泡法制备弹性体为基体的微孔导电复合材料应用于传感等领域提供了一定的指导.

    transl

    参考文献

    1

    Liu H.; Li Q. M.; Zhang S. D.; Yin R.; Liu X. H.; He Y. X.; Dai K.; Shan C. X.; Guo J.; Liu C. T.; Shen C. Y.; Wang X. J.; Wang N.; Wang Z. C.; Wei R. B.; Guo Z. H. Electrically conductive polymer composites for smart flexible strain sensors: a critical review. J. Mater. Chem. C, 2018, 6, 12121-12141. doi:10.1039/c8tc04079f [Baidu Scholar] 

    2

    董点点, 张静雯, 唐杰, 王军, 杨宽, 马忠雷, 张文博, 陈咏梅, 马建中. 基于天然高分子的导电材料制备及其在柔性传感器件中的应用. 高分子学报, 2020, 51, 864-879. doi:10.11777/j.issn1000-3304.2020.20114 [Baidu Scholar] 

    3

    He F. L.; You X. Y.; Wang W. G.; Bai T.; Xue G. F.; Ye M. D. Recent progress in flexible microstructural pressure sensors toward human-machine interaction and healthcare applications. Small Methods, 2021, 5, 2001041. doi:10.1002/smtd.202001041 [Baidu Scholar] 

    4

    Zhai W.; Xia Q. J.; Zhou K. K.; Yue X. Y.; Ren M. N.; Zheng G. Q.; Dai K.; Liu C. T.; Shen C. Y. Multifunctional flexible carbon black/polydimethylsiloxane piezoresistive sensor with ultrahigh linear range, excellent durability and oil/water separation capability. Chem. Eng. J., 2019, 372, 373-382. doi:10.1016/j.cej.2019.04.142 [Baidu Scholar] 

    5

    IIglio R.; Mariani S.; Robbiano V.; Strambini L.; Barillaro G. Flexible polydimethylsiloxane foams decorated with multiwalled carbon nanotubes enable unprecedented detection of ultralow strain and pressure coupled with a large working range. ACS Appl. Mater. Interfaces, 2018, 10, 13877-13885. doi:10.1021/acsami.8b02322 [Baidu Scholar] 

    6

    Sang Z.; Ke K.; Manas-Zloczower I. Design strategy for porous composites aimed at pressure sensor application. Small, 2019, 15, 1903487. doi:10.1002/smll.201903487 [Baidu Scholar] 

    7

    Rizvi R.; Naguib H. Porosity and composition dependence on electrical and piezoresistive properties of thermoplastic polyurethane nanocomposites. J. Mater. Res., 2013, 28, 2415-2425. doi:10.1557/jmr.2013.218 [Baidu Scholar] 

    8

    Zhai Y, Yu Y, Zhou K, Yun Z, Huang W, Liu H, Xia Q, Dai K, Zheng G, Liu C, Shen C. Flexible and wearable carbon black/thermoplastic polyurethane foam with a pinnate-veined aligned porous structure for multifunctional piezoresistive sensors. Chem Eng J, 2020, 382, 122985. doi:10.1016/j.cej.2019.122985 [Baidu Scholar] 

    9

    Huang Y.; Wang Y.; Sun X. H.; Guo X. H.; Zhang Y. Y.; Wang Z. Q.; Liu P.; Liu C. X.; Qiu J. H.; Zhang Y. G. Superelastic and large-range pressure sensor with hollow-sphere architectures for wearable electronic skin. Smart Mater. Struct., 2020, 29, 045014. doi:10.1088/1361-665x/ab73e1 [Baidu Scholar] 

    10

    Shao Y.; Luo C.; Deng B. W.; Yin B.; Yang M. B. Flexible porous silicone rubber-nanofiber nanocomposites generated by supercritical carbon dioxide foaming for harvesting mechanical energy. Nano Energy, 2020, 67, 104290. doi:10.1016/j.nanoen.2019.104290 [Baidu Scholar] 

    11

    Wei X, Cao X, Wang Y, Zheng G, Dai K, Liu C, Shen C. Conductive herringbone structure carbon nanotube/thermoplastic polyurethane porous foam tuned by epoxy for high performance flexible piezoresistive sensor. Compos. Sci. Technol., 2017, 149, 166-177. doi:10.1016/j.compscitech.2017.06.027 [Baidu Scholar] 

    12

    Fei Y, Chen F, Fang W, Xu L, Ruan S, Liu X, Zhong M, Kuang T. High-strength, flexible and cycling-stable piezo-resistive polymeric foams derived from thermoplastic polyurethane and multi-wall carbon nanotubes. Compos. B Eng., 2020, 199, 108279. doi:10.1016/j.compositesb.2020.108279 [Baidu Scholar] 

    13

    Suo Q. Q.; Zhang J. Y.; Cheng J.; Shi L. Preparation, microstructure, and piezoresistive behavior of conductive nanocomposite foams based on poly(1-butene) and carbon black. Appl. Phys. A, 2017, 123, 54. doi:10.1007/s00339-016-0662-y [Baidu Scholar] 

    14

    Zhang H. M.; Zhang G. C.; Gao Q.; Zong M.; Wang M. Y.; Qin J. B. Electrically electromagnetic interference shielding microcellular composite foams with 3D hierarchical graphene-carbon nanotube hybrids. Compos. Part A Appl. Sci. Manuf., 2020, 130, 105773. doi:10.1016/j.compositesa.2020.105773 [Baidu Scholar] 

    15

    Tewari A.; Gandla S.; Bohm S.; McNeill C. R.; Gupta D. Highly exfoliated MWNT-rGO ink-wrapped polyurethane foam for piezoresistive pressure sensor applications. ACS Appl. Mater. Interfaces, 2018, 10, 5185-5195. doi:10.1021/acsami.7b15252 [Baidu Scholar] 

    16

    Yu L. M.; Huang H. X. Temperature and shear dependence of rheological behavior for thermoplastic polyurethane nanocomposites with carbon nanofillers. Polymer, 2022, 247, 124791. doi:10.1016/j.polymer.2022.124791 [Baidu Scholar] 

    17

    赵凌云, 黄汉雄, 罗杜宇, 苏逢春. 复合材料柔软性对倒金字塔微结构阵列传感器性能的影响. 高等学校化学学报, 2021, 42, 2953-2960. doi:10.7503/cjcu20210281 [Baidu Scholar] 

    18

    Feng D.; Liu P. J.; Wang Q. Exploiting the piezoresistivity and EMI shielding of polyetherimide/carbon nanotube foams by tailoring their porous morphology and segregated CNT networks. Compos. Part A Appl. Sci. Manuf., 2019, 124, 105463. doi:10.1016/j.compositesa.2019.05.031 [Baidu Scholar] 

    19

    Dong D, Ma J, Ma Z, Chen Y, Zhang H, Shao L, Gao J, Wei L, Wei A, Kang S. Flexible and lightweight microcellular RGO@Pebax composites with synergistic 3D conductive channels and microcracks for piezoresistive sensors. Compos. Part A Appl. Sci. Manuf., 2019, 123, 222-231. doi:10.1016/j.compositesa.2019.05.019 [Baidu Scholar] 

    20

    Xu D. W.; Wang Q. Q.; Feng D.; Liu P. J. Facile fabrication of multifunctional poly(ethylene-co-octene)/carbon nanotube foams based on tunable conductive network. Ind. Eng. Chem. Res., 2020, 59(5), 1934-1943. doi:10.1021/acs.iecr.9b06163 [Baidu Scholar] 

    21

    Xiao S. P.; Huang H. X. Generation of nanocellular TPU/reduced graphene oxide nanocomposite foams with high cell density by manipulating viscoelasticity. Polymer, 2019, 183, 121879. doi:10.1016/j.polymer.2019.121879 [Baidu Scholar] 

    22

    Cao Y. Y.; Pang Y. Y.; Dong X.; Wang D. J.; Zheng W. G. To clarify the resilience of PEBA/MWCNT foams via revealing the effect of the nanoparticle and the cellular structure. ACS Appl. Polym. Mater., 2021, 3(8), 3766-3775. doi:10.1021/acsapm.1c00307 [Baidu Scholar] 

    More>

    657

    Views

    520

    Downloads

    4

    CSCD

    Alert me when the article has been cited
    Submit
    Tools
    Download
    Export Citation
    Share
    Add to favorites
    Add to my album

    Related Articles

    Electromagnetic Shielding Properties of Ethylene-vinyl Alcohol Copolymer/Carbon Nanotube Nanocomposite Foams
    Improving Cellular Structure of Microcellular Poly (butylene succinate)via Adding Low Content of Poly (lactic acid)
    Cellular Structure Manipulation of Microcellular PP/POE Blends Based on Phase Morphology

    Related Author

    No data

    Related Institution

    State Key Laboratory of Polymer Materials Engineering, College of Polymer Science and Engineering, Sichuan University
    Department of Mechanical and Industrial Engineering, University of Toronto
    Center for Polymer Processing Equipment and Intellectualization, South China University of Technology
    0